Steam-engine.



No. 632,677. Patented Sept, 5, I899.

J C. DEAN.

STEAM ENGINE.

(Application filed Sept. 12, 1898.) (No Model.) 2 Sheets-Shaet l.

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No. 632,677. Patented Sept. 5, I899.

'J. c. mam. STE-AM ENGINE! (Application filed Sept. 12,- 1698.)

(No Model.) 1 2 Sheets-Sheet 2.

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UNITED; ST

PATENT OFFlCEe JOHN C. DEAN, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO THE DEAN BROTHERS STEAM PUMP \VORKS, OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 632,677, dated September 5, 1899. Application filed September 12, 1898. Serial No.69Qj'75 0. -(ITo model.) A

To all whom it may concernr Be it known that'l, JOHN C. DEAN, a citi zen of the United Statea'residing at Indianapolis, in the county of Marion and State of Indiana, have inventedcertain new and useful Improvementsin Steam -Enginespf which the following is a specification. 5

The object of my said invention is to provide a means whereby the pistons of two steam-engines are caused to always move in opposite directions; and it consists in a means of coupling the valve-gear so that the steam shall be applied to the upper or outer end of one piston at the same instant of time that it is applied to the lower or inner end of the, other. Heretofore when'it has been desired to cause two engines to move oppositely to each other it has usually been done by coup ling the main piston-rodstogether. This has frequently caused a strain upon the working parts and a considerable waste of power, as frequently the valves in one steam chest would have a tendency 'to move slightly faster than those in the other, so that the force of the'steam upon the pistons would" be unequally applied and that pistons to which the steam was applied first would be held from movement by the coupling-bar against the force of the steam for a time, and thus said force would be neutralized and wasted.

By means of my invention I insure that the the steam force while securing anexactly tons ofthe engines.

I have illustrated my invention as applied to two direct-acting reciprocating steam-engines arranged to operate pumps and which in themselves are substantially of the construction and arrangement which I have heretofore employed, the novelty residing in the means of connecting the valve-gear by which the results above described are attained.

Referring to the accompanying drawings,

synchronous but opposite motion to the pisother of the collars'll.

which are made a part hereof and in which similar reference characters indicate similar parts, Figure 1 is a perspective view of a duplex steam-pumping apparatus embodying my present invention; Fig.2, a side elevation of the'same, the steam-cylinder and steamchest being shown in section, illustrating the main ports of the engine; Fig. 3, a front elevation, on a somewhat enlarged scale, of the upper portion of the apparatus shown in Fig. 1,. the steam-chests being shown 'in section and illustrating the valves therein and their operation; and Fig. 4, a detail sectional View on the dotted line 4 4 in Fig. 2.

j As heretofore stated,the engines and pumps thus shown are'inthemselves substantially of the construction and arrangement which I have been accustomed to make heretofore; but the operation will be briefly described for purposes of clearness/ Each steam-cylinder 1 hasitsown steampiston 2, piston-rod 3, valve movement, (presently to be described,) steam-chests 4c,&c. ,and both are constructed alike. A sleeve 5 is rigidly attached to each piston-rod3, and connected to this sleeve is a lever 6, which is fulcru'med at 7 upon a pivot carried by a wing "w of the frame, and the outer end of which extends out and connects with alink 8,which in turn is connected to a sleeve 9, loosely mounted upon the valve-rod 10 between collars 11 thereon, which limit the free movement or said sleeve. Said valve-rod 1O operates the auXiliaryslide-valve12, which slides on its three-ported valve-face and admits and exhausts alternately the steam from above and below the main-valve operating or auxiliary piston 13. This auxiliarypiston has attached thereto the main slide-valve 14, so

that the two move together. 1 This main slidevalve admits and exhausts steam alternately from above and below the main steam-pis tons 2. Any movement ofv the main piston 2, with its piston-rod 3,communicates movement (through the lever 6 and link 8) in the opposite direction to the sleeve 9, which slides freely on the valve-rod'lO and moves said valve-rod only when it strikes one or the As there is considerable lost motion between the sleeve 9 and the collars 11, the main steam-piston 3 will be to. the exhaust-port 21.

nearing the end of its stroke when the valverod begins to move.

Extending through the ends of the steam.- chests to the outside from the auxiliary or main-valve-operating pistons 13 are short piston-rods 15, upon the ends of which are links 16, by which they are connected to a centrally-pivoted vibrating lever 17, which is mounted on a pivot 18,extending out from the framework of the machine. This lever, arranged and operated in the manner specified,in combination with the auxiliary pistons, is the means whereby the result desired is prod uced,

and is the leading feature of my invention.

The operation may be stated as follows: When the main steam-piston in one of the engines has moved from the top to the bottom of the steam-cylinder, the corresponding auxiliary valve-rod 10 has moved in the opposite direction and the auxiliary slide-valve 12, attached to said valve-rod, has moved upward, opening the port 19 to steam and the port 20 At the moment the main steam-piston 2 has completed its downward stroke the auxiliary piston 13 is consequently forced upward to the limit of its movement and carries with it the main slidevalve 14. This movement of the main valve 14: on its valve-face opens the main port 22 to steam and the main port 23 to the main exhaust-port 24, which reverses the movement of the main piston 2. Steam is supplied from the branch pipe 25, and the spaces around the valves 12 and 13 are filled with live steam. When the main piston 2 reaches the upward limit of its stroke, the auxiliary valve 12 has moved downward, opening the port 20 to steam and the port 19 to the exhaust-port 21, causing the auxiliary piston 13 to move down ward, opening main port 23 to steam and the main port 22 to the exhaust-port 24, thus reversing the movement of the main piston 2.

It is to be noted that by my arrangement the auxiliary or main-valve-operating piston 13 is held at all times immovably at one end of its stroke, except when the main piston 2 is nearing the end of its stroke and is ready to reverse, and that at all times steam-pressure is on one end of the auxiliary piston 13 and the exhaust is open on the other end, excepting when the piston 2 is ready for its reverse stroke.

The foregoing description applies to the parts named in each of the two engines in every particular, it being understood, of course, that corresponding parts 'are at different positions at the same moment of time.

As the auxiliary or main-valve-operating pistons are connected by the lever 17, as heretofore described, they must always move in opposite directions, and therefore when the main steam-port on the left-hand side at the upper end of the steam-cylinder is open the main steam-port on the lower end of the righthand steam-cylinder is open, and therefore one steam-piston is forced upwardly while the other is forced downwardly.

The utility of this invention may be illustrated by the following example: Supposing the lefthand main piston has not quite reached the upperlimit ofits stroke, the steam would still be on the lower side of its auxiliary or main-valve-operating piston and the exhaust open to the other side. WVe now have steam on the bottom side of both auxiliary pistons, and as they are of the same diameter and are connected by the lever 17 they are balanced and will not move. The right-hand main steam-piston must wait until the lefthand main steam-piston has completed its stroke before it can reverse, and consequently the movement of the main pistons will always be in opposite directions, and neither can reverse until both have completed their stroke, and both make their return stroke simultaneously.

The drawings show the two engines arranged for operating twin-cylinder vertical air-pumps, such as are used in connection with condensing-engines. These air-pumps are single acting.- They discharge their air and water on the upstroke of the main piston only. As one or the other of the pistons is always ascending, there is a continuous discharge of air and water. The double-cylinder direct-acting engine, as shown, is peculiarly adapted to working twin-cylinder airpumps.

There are three ways that this apparatus may be operated: First, the engines may be operated in conjunction with each other, as is hereinbefore described. Second, the lever 17 may be detached from the auxiliary or main valve-operating pistons, and the two engines may then run independently of each other or in the ordinary and Well-known manner, each performing its own independent work. Third, by further detaching the link 8 on one of the valve-gears the auxiliary slidevalve 12 will remain at rest and the corresponding engine will not move while the other engine continues to operate. These are important features, because, as in case of accident, when, for example, the parts become deranged, it may be necessary to use one engine while the other is disabled, and in some cases it may be desirable to operate the engines independently. I thus secure in the same apparatus wherein the advantages above specified are secured a means whereby in case of necessity the apparatus may be operated separately and independently and also whereby each engine may be operated singly; or, in other words, the usual and ordinary functions of the engines remain available, while by the coupling means specified the advantages described are at the same time attained.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a duplex engine, the combination, of

the steam-cylinders, the pistons, the pistonrods, the steam-chests, the main valves therein, the auxiliary pistons attached to said main valves, rods connected with said auxiliary pistons and extending through one end of said steam-chests to the outside, each of said rods being hinged to opposite ends of a lever pivoted to the frame, said lever, auxiliary valves for controlling the supply of steam to said auxiliary pistons, and its exhaust, whereby said main valves are operated, and connections between the rods of said auxiliary valves and the main piston-rods, whereby said auxiliary valves are operated, substantially as set forth.

2. The combination, in a duplex steam-engine, of two ordinary steam-cylinders, two pistons, two piston-rods, two steam-chests having the usual live-steam and exhaust ports, two main valves, two auxiliary pistons for operating said main valves each having a piston-rod extending to the outside, two auxiliary valves adapted to control the ports which supply steam to said auxiliary pistons, each having a piston-rod extending to the outside, two levers pivoted to the framework and operated by the main piston-rods for operating the rods of said auxiliary valves, and-a pivoted bar also mounted on the framework and connected to the piston-rods of said auxiliary or main-valveoperating pistons, substantially as set forth.

In witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 8th day of September, A. D. 1898.

JOHN C. DEAN. [L. s.]

' Witnesses:

CHESTER BRADFORD, JAMES A. WALSH. 

